Is quantum physics behind your brain’s ability to think?

From consciousness to long-term memories, the human brain has some peculiar computing abilities – and they could be explained by quantum fuzziness

MATTHEW FISHER was wary of how his peers would react to his latest project. In the end he was relieved he wasn’t laughed out of court. “They told me that this is sensible science – I’m not crazy.”

Certainly nothing in Fisher’s CV says crazy. A specialist in the quantum properties of materials, he worked at IBM and then at Microsoft’s Research Station Q developing quantum computers. He is now a professor at the Kavli Institute for Theoretical Physics at the University of California Santa Barbara. This year he won a share of the American Physical Society’s Oliver E. Buckley prize in condensed matter physics, many recipients of which have gone on to win a Nobel.

The thing was, he had broached a subject many physicists would rather simply avoid.

“Does the brain use quantum mechanics? That’s a perfectly legitimate question,” says Fisher. On one level, he is right – and the answer is yes. The brain is composed of atoms, and atoms follow the laws of quantum physics. But Fisher is really asking whether the strange properties of quantum objects – being in two places at once, seeming to instantly influence each other over distance and so on – could explain still-perplexing aspects of human cognition. And that, it turns out, is a very contentious question indeed.